Methods of making flocked solvent activatable stiffening and shoe lining materials



1963 s. M. GRISWOLD 3,073,715

METHODS OF MAKING FLOCKED SOLVENT ACTIVATABLE STIFFENING AND SHOE LINING MATERIALS Original Filed Aug. 7, 1958 [nven for Jtanley M. Griswold B his fhtorne Patented Jan. 15, 1963 This invenltion relates to shoemaking and more particula-rly to methods of making sheet material for providing solvent activatable stiffening elements for shoe uppers. This application is a division of my application Serial No. 753,717, filed August 7, 1958, new Patent No. 3,022,188.

Much effort has been devoted in the past to provide economic materials for and methods of stiffening selected portions of shoe uppers. However, the difficulty of providing a stiffening element for the heel portion or an unlined shoe which combines. pleasing appearance, good wearing qualities, and ease of activation with initial conformability has left much to be desired in materials hitherto available. i

In the past there has been developed a' stiffener material comprising a porous base impregnated in discontinuous form with a stiffener agent such as cellulose nitrate or polystyrene resin and hence adapted to be solvent activated to cause the material to become stiff after evaporation of the solvent. Stiffener elements died out of such material have been used extensively for shoe toe stiffening. However, such material has had little use in heel end stiffening, particularly since efforts to provide a layer of flock on such material for use in unlined shoes had proved unsatisfactory because the flock to- .gether Withlayer of'flocking adhesive tended to crack on flexing of the material and to peel away too easily from the underlying surface of the stiffener sheet.

It is accordingly an object'of the present invention to: provide an improved method of making flocked solvent activatable sheet stiffener material by the-use of which method material having securely bonded flock may be.

prepared.

To this end and in accordance with a feature of th invention, a method is provided featuring the steps of treating a single napp'ed fabric'b'ase to deposit therein in discontinuous form a stiffeningagent coalescible by solvent, said treatment including impregnating the fabric with a liquidicomposition. comprising a stiffening agent and removing from the unnapped side of the fabric suf licient of the impregnating composition toeXpose th'e sursolvent activation through swelling of the flocking ad V hesive by certain solvents like toluol.

Further features and advantages of the present invention will best be understood by reference to the following description in connection with the appended drawings, in which FIG. 1 is a counter dyed out of material made in accordance with the present invention;

FIG. 2 is a greatly enlarged partial seotionthrough a sheet of such material; and

FIG. 3 is a diagrammatic illustration of a method of manufacturing the material of the present invention. Referring to FIGS. 1 to 3, the sheet material provided by the method of the present invention comprises a base 10 of single mapped fabric such as cotton flanel carrying in discontinuous form a stiffening agent capable of being coalesced upon activation with a solvent. Conveniently, the material may be prepared by passing-the base through a bath 12 containing a liquid mixture of a stiffening 'agent in' a form appropriate to deposit the stiffening agent in the base ina discontinuous form when the sheet is thereafter dried. Two well-known stiffening agents used in preparingsolvent ac-tivatable stiffener material are cellulose nitrate and polystyrene. Either of-these agents may be used although I prefer the cellulose nitrate because of its better adhesive qualities; Where cellulose nitrate is employed as the stiffening agent, the fabric 10 is passed through the bath 12'containing the cellulose nitrate dissolved in a solvent. After leaving the bath 12, the fabric is passed between stripping rolls 14 which are adjusted to remove sufficient of the cellulose solution from the unnapped side of the fabric 7 so that after drying there is'not'sufi'icient stiffening agent left on-this side of the material completely to cover the threads of the fabric thereby permitting the flocking adhesive to come into direct contact therewith. From the stripping rolls, if the stiffening agent is cellulosenitrate, the fabric 10 passes through a water-bath 16. This bath is not employed Where the stiffening agent is polystyrene which is preferably applied in the form of the latex of the type disclosed in United States Letters Patent No.

' 2,760,884, issued August 28,- 1956, on an application filed face of the fabric in its treated and dried condition, dry

ing the treated fabric, applying a layer of flocking ad,"

hesive to the unnapped surface, applying a layer of flock .over the adhesive layer and drying the adhesivepfihev successof the method depends to ajlarge extent upon the use of a single napped fabric and in the, removal from theunnapped surface thereof of sufficient stiffening agent wto expose the surface of the fabricand thus provide a ",firm base for the flocking adhesive. -The material provided "by-1 the 'methodofgthe present invent-ion comprises a single'napped fabric impre'gn ated,, with a-solvent coalescible stifiening agent in discontinu 7 (ins term and a layer'of flock bondedto the ,pnnapped lsiicleby aflayer ofiadhesivegwhich,instead'of; imposed ion-a layer of stiifening ageitcov, iring the fabric,

"his directly engaged with the fabric surface;

Preferably, "also the flocking,adhesive will be porious to minimize'dan'ger'oflblistering theflockfsiirface during i porousadhesive layer it is ,usuall'y'sufficientto employ} by application of solven' only tothe unflockedsurfac mFIGE'l/ lnithedry for with out lcrackin'g"theflocked securely ibo'nded to the fabricfbasey removable. Previous efforts to flee impregnate/din discontinu to cure it, and the finished material-is then taken up on j solvent, made,'by'B; B. Chemical Co., Cambri dge, M s. I p In some cases, howeve'rflwa conventional flocking adhesive (is i fis sr aterial,

i If The h -mater al ma in the name of George Leonard Graf, Jr. The fabric is then'dried in a drying' oven 18 and after passing over idler rollers 20, proceeds to a conventional flocking of the unnapped surface wherein a flocking adhesive 32 is applied from a trough 22 and flock 34 is applied from a second trough 24 followed by beating with a bar 26. After this the stiffener material passes through an oven 28 to evaporate the solvent-of the flocking-adhesive and a roll 30. The layer '32 of flocking adhesive, shown in FIG. 2, applied in this .manner maybe either porous or; I nonporous as'desired. porous -film" of flocking ad hesive is preferable to preventfdistortion, blistering or I swelling on contact with some solvents; To provide} a low solids and relatively low, viscosity adhesive", such as;

#1734, a curing neoprene flock'adhesive using aromatic may be employed whe'r activation .w i11"-be penformed 'shoeilining;elementssichta U M T a this ounter 'maiy be flexed surface and ;fiock ;is "so had resulted in a material having defects corresponding to the aforesaid good qualities of the present material which I believe arose because of the substantial layer of stiffening compound covering the fabric surface to which it was quite loosely bound and which afiorded a very insecure surface for the flock anchorage through the flocking adhesive not only before but during activation.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United tates is:

1. The method of making sheet stiffener material for shoes and the like comprising treating a single napped fabric base to deposit therein in discontinuous form a solvent coalescible stiffening agent, said treatment ineluding impregnating the fabric with a liquid composition comprising said agent and removing from the unnapped side of the fabric sufiicient composition to expose the fabric surface in dried condition, applying to said unnapped side of the fabric a layer of flocking adhesive and applying a layer of flock over said adhesive.

2. The method of making sheet stifiener material for shoes and the like comprising treating a single napped fabric base with a solvent coalescible stiffening agent, said treatment including impregnating the fabric with a liquid composition comprising said agent and removing from the unnapped side of the fabric sufiicient composition to expose the fabric surface in dried condition, applying to said unnapped side a flocking adhesive in solvent solution, applying a layer of flock over the adhesive, and applying heat to evaporate the solvent and cure the adhesive.

3. The method of making sheet stiliener material for lining shoes and the like comprising treating a single napped fabric base with a solvent coalescible stiffening agent to dispose said agent within the fabric, the surface coating of said agent on the unnapped side of the fabric being sufiicient to embed all threads of said fabric, applying a layer of flocking adhesive over said unnapped side and applying a layer of flock over the adhesive.

4. The method of making sheet stiffener material for shoes and the like comprising treating a single napped fabric base to deposit therein in discontinuous form a solvent coalescible stiffening agent, said treatment including impregnating the fabric with a liquid composition comprising said agent while leaving on the unnapped side of the fabric insufficient composition to cover completely the fabric surface in dried condition, applying to said unnapped side of the fabric a layer of flocking adhesive which is porous in its dried condition and applying a layer of flock over said adhesive.

References Cited in the file of this patent UNITED STATES PATENTS 25,192 Goodyear Aug. 23, 1859 1,391,932 Beckwith et a1 Sept. 27, 1921 2,067,239" Mayo et a1; Jan. 12, 1937 2,358,204 Bird Sept. 12, 1944 2,567,327 Ewing Sept. 11, 1951 2,619,441 Levy' Nov. 25, 1952 2,887,400 Pollack May 19, 1959 

1. THE METHOD OF MAKING SHEET STIFFENER MATERIAL FOR SHOES AND THE LIKE COMPRISING TREATING A SINGLE NAPPED FABRIC BASE TO DEPOSIT THEREIN IN DISCONTINUOUS FORM A SOLVENT COALESCRIBE STIFFENING AGENT, SAID TREATMENT INCLUDING IMPREGNATING THE FABRIC WITH A LIQUID COMPOSITION COMPRISING SAID AGENT AND REMOVING FROM THE UNNAPPED SIDE OF THE FABRIC SUFFICIENT COMPOSITION TO EXPOSE THE FABRIC SURFACE IN DRIED CONDITION, APPLYING TO SSAID UNNAPPED SIDE OF THE FABRIC A LAYER OF FLOCKING ADHENSIVE AND APPLYING A LAYER OF FLOCK OVER SAID ADHESIVE. 